The invention relates to the field of floor gratings, particularly of the type comprising a series of rigid tread rails, typically formed of extruded aluminum, arranged in a side-by-side series, with a narrow spacing between adjacent rails. The tread rails are rigidly secured in the described configuration and typically are installed in a suitable recess provided in the floor surface. The arrangement is such that the upper surfaces of the tread rails form, in effect, a continuation of the surrounding floor surface.
Floor grating structures of the general type described are well known in the art. The viehmann, et al. U.S. Pat. No. 3,383,822 and the Reifsnyder U.S. Pat. No. 4,112,640 are representative of known constructions of these devices.
In the construction of floor gratings, consideration is given to the manner in which the tread rails are secured together and held in predetermined spaced relation. The desired objective is to accomplish the desired spacing and securement in a manner that accommodates economical manufacture and assembly of the grill structures. The Viehmann, et al. and Reifsnyder disclosures illustrate useful techniques for this purpose wherein the tread rails are provided with aligned openings for the reception of a plurality of spacing bars arranged to extend transversely from one side of the assembly to the other. The tread rail openings accommodate insertion of the spacing bars in a predetermined rotational orientation. After the initial insertion, the spacing bars are rotated into a locking position, in which the tread rails are affixed in the desired spaced relation. The arrangement is also such that final positioning of the spacing bar serves to lock the assembly in a desired rectangular orientation, preventing skewing of the assembly into a parallelogram configuration. Various techniques are then employed to secure the spacing bars in their final positions. Some manufacturers utlize tack welds, others provide arrangements for deforming one or both of the assembled members in some way that prevents rotation of the spacing bar out of its assembled position.
The present invention is directed to improvements in the construction of otherwise known floor grating structures, especially of the general type disclosed in the Reifsnyder U.S. Pat. No. 4,112,640. In particular, the structure of the present invention incorporates an improved and simplified spacing bar arrangement which provides for structural improvement in the spacing bar and more importantly, provides for a simplified and highly effective facility for securing the spacing bar in its final, assembled position, avoiding the need for tack welds or complex mechanical operations.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment of the invention and to the accompanying drawings.